Fire retardant container

ABSTRACT

A fireproof container having an outer housing, an inner housing, and heat protection means disposed between the outer and inner housings. The heat protection means includes an ablative material.

United States Patent Gamble [54] FIRE RETARDANT CONTAINER [72] Inventor:Edward R. Gamble, Clayton, Mo.

[73] Assignee: American Air filter Company, Inc.,

Louisville, Ky.

22 Filed: Nov. 18,1970

21 Appl. No.: 90,727

52 U.S.Cl ..109/29, 220/9 R, 109/84 51 Int. Cl ..E05g 1/00 58FieldofSearch ..109/29-34, 76,

109/80, 84; 220/9 B, 9 A, 9 LG, 9 R

[ NOV. 14, 1972 Primary Examiner-Dennis L. Taylor Attorney-Charles G.Lamb and Ralph E. Brick [5 7] ABSTRACT A fireproof container having anouter housing, an [56] References Clted inner housing, and heatprotection means disposed UNTED STATES PATENTS between the outer andinner housings. The heat protection means includes an ablative material.1,038,428 9/1912 Pederson ..109/84 2,586,873 2/1952 Siple ..109/84 X 5Claim, 6 Drawing Figures I 5 9% $i f \7 \g/ 1 7 19 1 ax FIRE RETARDANTCONTAINER BACKGROUND OF THE INVENTION Fireproof containers are wellknown in the prior art. Most of these containers provide adequateprotection for the contents stored therein against destruction by firebut are relatively high in cost, high in weight, and low in usablevolume in comparison with the overall dimensions of the container. Inrecent years there has been considerable activity in reducing the costand weight of these containers while at the same time increasing theusable volume. Most of the activity has centered around insulationswhich could be installed between the outer housing or frame of thecontainer and the contents inside which are to be protected. One familyof insulations now being used in fireproof containers is the hightemperature resistant molded plastic compositions. However, for manyapplications these fireproof containers have still been found to be tooheavy and will not protect the contents of the container at hightemperatures for extended periods of time.

SUMMARY OF THE INVENTION In the present invention, it is recognized thatit is desirable to provide a fireproof container being low in cost,light in weight, and large in usable volume. Furthermore, it isrecognized that it is desirable to provide a fireproof container whereinthe contents are adequately protected against the severest conditions ofexposure to, for example, burning brush, wood, and tentage.

The present invention advantageously provides a straight forwardfireproof container useful for the protection of valuables against theseverest conditions of exposure to burning brush, wood, tentage, and thelike.

The present invention also provides a fireproof container utilizingablative materials to protect the contents of the container when exposedto high temperatures for extended periods of time. The ablativematerials, as used hereinafter, refer to those materials that arenon-combustible and sublimate at elevated temperatures. These materialsdissipate energy from heat, such as a fire, with an accompanying loss ofmaterial. Many of these materials are utilized in the art of rocketry asheat dissipators for rockets which reenter the earths atmosphere atextremely high velocities. US. Pat. Nos. 3,022,190; 3,395,035; and3,506,607 describe in detail many of the ablative materials that may beused as heat dissipators in rocket re-entry. These materials have nowbeen found useful in fireproof containers when applied in the mannerhereinafter described.

The present invention further provides a fireproof container which islight in weight and economical in cost.

Various other features of the present invention will become obvious tothose skilled in the art upon reading the disclosure set forthhereinafter.

More particularly, the present invention provides for a fireproofcontainer comprising: an outer housing; an inner housing disposed withinsaid outer housing in spaced relation therefrom to define a chambertherebetween, said inner housing defining a plenum and having an openingtherein; heat protection means disposed in said chamber and extendingbetween said outer housing and said inner housing, said heat protec- LIItion means including an ablative material; vent means adapted forventing gaseous products of said ablative material from said chamber inthe event said container is exposed to excessive heat; and closure meansadapted to communicate with said inner housing, said closure meansincluding an outer wall and an inner wall with heat protection meansdisposed therebetween.

It is to be understood that the description of the examples of thepresent invention given hereinafter are not by way of limitation, andthat various modifications with the scope of the present invention willoccur to those skilled in the art upon reading the disclosures set forthhereinafter.

FIG. 1 is a perspective view of a container assembly in accordance withthe present invention;

FIG. 2 is a perspective view of a container assembly, without the lid,in accordance with the present invention;

FIG. 3 is a vertical sectional view of a container assembly, taken alongthe line 3-3 of FIG. 2;

FIG. 4 is a partial vertical sectional view of a container assembly,taken along the line 4-4 of FIG. 2;

FIG. 5 is a perspective view of a lid of a container assembly inaccordance with the present invention; and,

FIG. 6 is a vertical sectional view of a lid of a container assemblytaken along the line 6-6 of FIG. 5.

Referring to FIGS. 1 and 2 of the drawing there is illustrated a lid 10having a top wall 3 with downwardly extending sides 14. On eachdownwardly extending side 14 there is provided a latch 4. Lid 10 isfurther provided with a handle 1 for lifting and removing the lid 10from the container 20. Vents 2a and 2b are provided for venting ablativegases, hereinafter described, from the container 20 and the lid 10whenever the container 20 and the lid 10 are exposed to excessive heat.

The container 20 is comprised of an outer housing including outer endwalls 7 and outer side walls 9, inner housing 33, and heat protectionmeans, hereinafter described, disposed between and in communicativerelation with outer walls 7 and 9 and inner housing 33. Outer end walls7 are provided with vertically extending sections 8 and horizontallyextending top sections 11 to outer fit side walls 9. Rivets 34 are usedto attach sections 8 and 1 1 to walls 9. Fixedly attached to the endwalls 7 are upwardly extending latch cases 6 which are positioned to bereceived by latches 4. The horizontally extending top sections 11 havedisposed therein a plurality of vents 13 for venting ablative gases,hereinafter described, from the container 20. Outer side walls 9 areprovided with horizontally extending top sections 12 which underfithorizontally extending top sections 11. Fixedly attached to the outerside walls 9 are upwardly extending latch cases 6 which are positionedto be received by latches 4.

Inner housing 33 is comprised of side walls 5, end walls 21, and abottom wall 32 (FIG. 3).

FIGS. 3 and 4 show one advantageous embodiment of a heat protectionmeans within the scope of the present invention.

FIG. 3 illustrates that the heat protection means disposed between theouter side wall 9 and the inner side wall 5 includes outer ablativematerial 16, horizontally extending honeycomb material 17, and innerablative material 19, respectively. Ablative material 16 and ablativematerial 19 may be the same or different ablative materials. It is alsoseen in FIG. 3 that the horizontally extending top section 12 of outerside walls 9 and inner side walls are joined by rivets 29. Disposedbetween and in communicative relation with section 12 and walls 5 isasbestos paper 22.

FIG. 3 further illustrates that the heat protection means disposedbetween the bottom wall 25 of the container 20 and the bottom wall 32 ofthe inner housing 33 includes outer ablative 16, vertically extendinghoneycomb 18, and inner ablative 19, respectively.

In FIG. 4 it is seen that the heat protection means disposed between theouter end wall 7 and the inner housing end wall 21 includes outerablative material 16, horizontal extending honeycomb 17, and innerablative material 19, respectively. Horizontally extending top section11 of outer end wall 7 and inner end wall 21 are joined by rivets 29.Disposed between and in communicative relation with sections 11 and 21is asbestos paper 35.

Referring now to the lid as illustrated in FIGS. 5 and 6, it is seenthat the heat protection means is disposed between the outer wall 3 andthe inner wall 28. The heat protection means includes outer ablativematerial 23, outer vertically extending honeycomb 24-, inner verticallyextending honeycomb 26, and inner ablative material 27, respectively.The outer ablative material 23 and the inner ablative material 27 may bethe same or different materials. Outer vertically extending honeycomb 24and the inner vertically extending honeycomb 26 may be the same ordifferent materials as well as the same or different configurations.Further, since the honeycomb material is primarily used as a support, itis not necessary to have two honeycomb sections, but only one. If onlyone honeycomb section is used, then the honeycomb will be fabricated tofit the irregular shape of lid 10.

Outer wall 3 is provided with downwardly extending sides 14 and innerwall 28 is provided with Z-shaped upwardly extending sides 15. Disposedbetween the sides 14 and the sides is asbestos paper 31 and a feltedmaterial 30 having high temperature insulative properties. One preferredfelted material is a felted material manufactured by Johns-Manvilleunder the trade name, Cerafelt. The felted material 30 is configured tofit the horizontal extending section 36 of the Z-shaped upwardlyextending sides 15, the asbestos paper 31, and the downwardly extendingsides 14. The felted material 30 communicates with horizontallyextending top sections 11 and 12 of container (FIG. 2) whenever lid 10is in mating relationship with container 20.

The inner wall 28 with the upwardly extending sides 15 is constructed tofit within the inner housing 33 (FIG. 2) of the container 20 (FIG. 2),the sides 15 being in communication with the side walls 5 and the endwalls 21 of the inner housing 33.

In the construction of a fireproof container of the instant invention,variations of the container design, as illustrated in the drawings, canbe made to provide any desired internal capacity. The design will bedependent upon, among other things, the volume and weight of thecontents to be protected, and the fire hazards that the container may besubjected to. For example, one container which was designed to handle a30-inch stack of 8% X 11-inch documents and to protect these contents ina fire at l550 F. for 30 minutes with a temperature rise of 350 F. orless, the outer walls 7, 9, and 25 were fabricated from an l -gaugecold-rolled steel and the inner housing 33 was fabricated from 0.050-inch anodized aluminum. The ablative material used was a compositionhaving a sublimation temperature of about 400 F. This material wasobtained from Thermal Systems Inc. and was identified as FP-T22068Thermo-Lag.

In the choice of ablative materials to be used, it must be determinedthat at the range of temperatures under which it is to be subjected, itmust sublime (change from the solid state to the vapor state) and notsimply decompose. In fireproof containers the critical temperature rangeto which the container may become exposed is from the kindlingtemperature of the material to be protected, to the maximum normallyencountered by fires fed by wood and similar building materials, thatis, approximately 200 to l600 F., and the temperature rise of thecontainer contents may be from existing ambient temperature to thekindling point of the material, which will vary from 60 F. toapproximately l600 F.

Further, the amount of ablative material required will be that amountsufficient to withstand the anticipated critical temperatures up to 60minutes while not allowing the temperature of the inside of thecontainer to rise above the aforementioned limits. Thus, if the maximumheat rise of the contents of the container cannot be above, for example,about 400 F, then an ablative composition having a sublimationtemperature of about 450 or less would be the proper ablative to use Ifthe contents to be protected can withstand temperatures in theneighborhood of 1000 F., then an ablative having a sublimationtemperature of 1050 F. or less would be acceptable. The amount ofablative necessary would depend upon the latent heat of sublimation ofthe ablative and the total amount of heat such ablative would be exposedto. Some examples of ablative materials that may be used includeammonium fluoroborate which sublimes at about 450 F., molybdenumhexacarbonyl which sublimes at about 230 F., chromium trichloride whichsublimes at about 180 F., mercuric sulfide (red) which sublimes at about1075 F., ammonium chloride which sublimes at about 635 F., and the like.

In preparing a use composition of an ablative it may be necessary to adda binder, such as, for example, a resorcinal-phenol-formaldehyde resin;and accelerator to speed-up the curing of the binder, such as, forexample, paraformaldehyde; a heat transferring material, such as, forexample, graphite; and a carrier for the ablative with theaforementioned binder, accelerator, and heat transferring material, suchas, for example, ethyl alcohol. The use composition may include fillersand other ingredients which are compatible with the ablative material inorder to assist in the application of the ablative material in thefireproof container by methods hereinafter described. These compositionscontaining other materials which assist in preparation of the ablativematerial into a use composition are within the scope of this invention.

In applying the ablative composition in the fireproof container at thepoints described in the aforementioned discussion of the drawings, theablative composition may be poured and troweled or sprayed. In theinstant invention pouring and trowelling has been a preferred method ofapplying.

in one embodiment of fabricating a fireproof container of the instantinvention, the outer walls 7, 9 and 25 of container 20 are constructedand riveted together with rivets 34, the rivets 34 and the walls 7, 9and 25 being suitable for the temperature range anticipated. The rivetedouter walls 7, 9 and 25 are then laid on one wall and a predeterminedamount of ablative material 16 is poured in and spread uniformly with atrowel. Honeycomb material 17, which is usually a fire-retardantcardboard, is then laid on the ablative and pressed in firmly. Theablative, in addition to its aforementioned properties, acts as a glueor bonding agent. Each of the other walls is done in order, adding theablative and then pressing in the honeycomb, with the bottom wall 25being the last to be completed. Ablative material 19 is then added andthe inner housing 33 is then lowered into place. Asbestos paper 22 isinserted between inner housing 33 and the horizontally extending topsections 11 and 12. Inner housing 33 is then riveted with rivets 29 tothe horizontally extending top sections 1 1 and 12 of the outer walls 7and 9.

Ablative material 19 is not normally required in the practice of theinstant invention but is added in the above discussed embodiment inorder to increase the strength of the container 20.

Lid is fabricated in a similar fashion as the container 20. That is,outer wall 3 is cut with downwardly extending sides 14 and ablativematerial 23 is added, uniformly to the underside of wall 3. Honeycombmaterial 24 is pressed into the ablative material 23. Asbestos paper 31is then inserted into the space between the honeycomb material 24 andthe sides 14. lnner vertically-extending honeycomb material 26 is theninserted in place and ablative material 27 is added. Inner Wall 28 ofthe lid 10 with upwardly extending sides configured to outer fit thehoneycomb 26 with ablative material 27 attached thereto and thehoneycomb 24 is then pressed into place. Felt 30, having a hightemperature adhesive backing and being cut to fit the sides 15, theasbestos paper 31 and the sides 14, are then pressed firmly into place.

Handle 1, locks 4, and lock cases 6 are added to the lid 10 and thecontainer by any known prior art method.

The above discussion only illustrates one method of practicing theinstant invention. By varying the structure of the lid 10 and thecontainer 20 it is possible to fabricate fireproof containers in theform of file boxes, multiple-drawer file cabinets, vaults, and the like.Further, the closure means, such as lid 10, can be provided with hingedas well as removable means, with the hinged or removable means beinglocated on the top as well as the sides. Thus, numerous variations andsubstitutions may be made without departing from the spirit and scope ofmy invention and it is to be understood that no limitation is intendedwith respect to the instant invention, other than as defined by theclaims.

What is claimed is:

1. A fireproof container comprising:

an outer housing; an inner housing disposed within said outer housing inspaced relation therefrom to define a chamber therebetween, said innerhousing defining a plenum and having an opening therein;

heat protection means disposed in said chamber and extending betweensaid outer housing and said inner housing, said heat protection meansincluding an ablative material; vent means adapted for venting gaseousproducts of said ablative materials from said chamber in the event saidcontainer is exposed to excessive heat; and closure means adapted tocommunicate with said inner housing, said closure means including anouter wall and an inner wall with heat protection means disposedtherebetween.

2. The fireproof container of claim 1 wherein said heat protection meansincludes a material of honeycomb configuration.

3. The fireproof container of claim 2 wherein said ablative material isdisposed between and in communicative relation with said outer housingand said material of honeycomb configuration.

4. The fireproof container of claim 2 wherein said ablative material isdisposed in two layers, a first layer being disposed between and incommunicative relation with said outer housing and said material ofhoneycomb configuration and a second layer is disposed between and incommunicative relation with said material of honeycomb configuration andsaid inner housing.

5. The fireproof container of claim 1 wherein said heat protection meansof said closure means includes an ablative material and a material ofhoneycomb configuration wherein said ablative material is disposedbetween said top wall of said closure means and said material ofhoneycomb configuration.

1. A fireproof container comprising: an outer housing; an inner housingdisposed within said outer housing in spaced relation therefrom todefine a chamber therebetween, said inner housing defining a plenum andhaving an opening therein; heat protection means disposed in saidchamber and extending between said outer housing and said inner housing,said heat protection means including an ablative material; vent meansadapted for venting gaseous products of said ablative materials fromsaid chamber in the event said container is exposed to excessive heat;and closure means adapted to communicate with said inner housing, saidclosure means including an outer wall and an inner wall with heatprotection means disposed therebetween.
 2. The fireproof container ofclaim 1 wherein said heat protection means includes a material ofhoneycomb configuration.
 3. The fireproof container of claim 2 whereinsaid ablative material is disposed between and in communicative relationwith said outer housing and said material of honeycomb configuration. 4.The fireproof container of claim 2 wherein said ablative material isdisposed in two layers, a first layer being disposed between and incommunicative relation with said outer housing and said material ofhoneycomb configuration and a second layer is disposed between and incommunicative relation with said material of honeycomb configuration andsaid inner housing.
 5. The fireproof container of claim 1 wherein saidheat protection means of said closure means includes an ablativematerial and a material of honeycomb configuration wherein said ablativematerial is disposed between said top wall of said closure means andsaid material of honeycomb configuration.